Production method and production apparatus for magnetic recording medium

ABSTRACT

A production method and a production apparatus for a magnetic recording medium, which enable the efficient production of a discrete type magnetic recording medium, while reliably preventing any deterioration of the partitioned recording elements. The magnetic recording medium production apparatus includes: recording layer processing device, which by forming a plurality of grooves, with a minute spacing therebetween in a planar direction, in an intermediate of a magnetic recording medium comprising a continuous recording layer, partitions the continuous recording layer into a plurality of partitioned recording elements; non-magnetic body filling device for filling the grooves between the partitioned recording elements with a non-magnetic body; smoothing device for smoothing the surface of the partitioned recording elements and the non-magnetic body; protective layer formation device for forming a protective layer on the partitioned recording elements and the non-magnetic body; and vacuum retention device which houses the recording layer processing device, the non-magnetic body filling device, the smoothing device, and the protective layer formation device, and maintains the environment surrounding the intermediate in a state of vacuum.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a production method and aproduction apparatus for a magnetic recording medium.

[0003] 2. Description of the Related Art

[0004] In recent years, magnetic recording media such as hard disks andthe like have undergone significant increases in recording density as aresult of improvements including miniaturization of the magneticparticles that make up the recording layer, development of newmaterials, and miniaturization of head processing technology, and it isenvisaged that the future will bring further increases in recordingdensity.

[0005] However, increasing the recording density by conventionalimprovement techniques such as miniaturization of the magnetic particleshas now reached its limit, and discrete type magnetic recording media,in which a continuous recording layer is partitioned into a plurality ofpartitioned recording elements, and a non-magnetic body is then used tofill the grooves between these partitioned recording elements, have beenproposed (for example, see Japanese Patent Laid-Open Publication No. Hei9-97419) as an example of magnetic recording media which will enablefurther improvements in recording density.

[0006] Dry etching techniques such as reactive ion etching are examplesof processing techniques that can be used to create minute partitionswithin a continuous recording layer (for example, see Japanese PatentLaid-Open Publication No. Hei 12-322710).

[0007] Furthermore, embedding techniques that utilize wet processes suchas those used in the field of semiconductor production (for example, seeJapanese Patent Laid-Open Publication No. Hei 13-323381) can be used toachieve the non-magnetic filling described above.

[0008] If level differences occur between the surfaces of thepartitioned recording elements and the non-magnetic body then problemssuch as instability of the head flying movement and the accumulation offoreign matter can arise, and consequently the surface of thepartitioned recording elements and the non-magnetic body are preferablysmoothed. This smoothing operation can also be conducted usingprocessing techniques used in the field of semiconductor production,such as CMP (Chemical Mechanical Polishing) techniques based on wetprocesses.

[0009] In addition, a wet cleaning technique used in semiconductorproduction (for example, see Japanese Patent Laid-Open Publication No.Hei 12-091290) can be used for removing foreign matter from the surfaceof the partitioned recording elements.

[0010] However, if the type of dry etching used in a semiconductorproduction process is used, as is, for processing a continuous recordinglayer, then sections of the partitioned recording elements are prone toproblems of deterioration such as oxidation and corrosion. Deteriorationof the partitioned recording elements may also occur over a period oftime following production. In addition, the action of solvents and thelike during other wet processes such as cleaning can also cause problemssuch as oxidation and corrosion within some sections of the partitionedrecording elements. Another problem arises in that the use of wetprocesses increases the likelihood of contamination of the surface ofthe partitioned recording elements with foreign matter. These problemsof deterioration and contamination of the partitioned recording elementscan cause a loss of precision in the recording and reading ofinformation.

[0011] Furthermore, combining dry processes and wet processes createsadditional problems in that transportation of work (intermediates of themagnetic recording medium) becomes more difficult, and productionefficiency deteriorates.

[0012] In other words, because magnetic recording media have uniqueproblems, including the fact that the magnetic material tends to beprone to oxidation, the use of processing techniques that are effectivewithin other fields, such as semiconductor production, during theproduction of magnetic recording media results in a variety of problemssuch as oxidation of the magnetic material, and accordingly producingdiscrete type magnetic recording media with good efficiency, whilepreventing deterioration of the partitioned recording elements, hasproven to be very difficult.

SUMMARY OF THE INVENTION

[0013] The present invention takes the problems described above intoconsideration, and has an object of providing a production method and aproduction apparatus for a magnetic recording medium, which enable theefficient production of a discrete type magnetic recording medium, whilereliably preventing any deterioration of the partitioned recordingelements.

[0014] The present invention is able to resolve the above problems bymaintaining the work environment in a state of vacuum, and conductingprocessing of the continuous recording layer using dry processes.Completely isolating the partitioned recording elements from theatmosphere is very effective in reliably preventing any deterioration ofthe partitioned recording elements, and consequently the steps from theformation of the partitioned recording elements through to the formationof the protective layer are preferably all conducted with the workenvironment maintained in a state of vacuum.

[0015] In this specification, the term “vacuum” is not restricted to thedefinition of a state in which the air pressure is 0 [Pa], but ratherdefines a state of extremely low air pressure in which the pressure iswithin a range from approx. 0 to 100 [Pa]. Furthermore, the term“magnetic recording medium” is not restricted to hard disks, floppydisks (registered trademark) and magnetic tapes and the like, which useonly magnetism for the recording and reading of information, but alsoincludes magneto-optical recording media such as MO (Magnet Optical)disks which combine both magnetic and optical characteristics.

[0016] Accordingly, various exemplary embodiments of this inventionprovide as described below.

[0017] (1) A method of producing a magnetic recording medium comprising:a recording layer processing step, which by forming a plurality ofgrooves, with a minute spacing therebetween in the planar direction, inan intermediate from a production process for a magnetic recordingmedium produced by forming a continuous recording layer on top of asubstrate surface, partitions the continuous recording layer into aplurality of partitioned recording elements; a non-magnetic body fillingstep for filling the grooves between the partitioned recording elementswith a non-magnetic body; and a protective layer formation step forforming a protective layer that protects the partitioned recordingelements and the non-magnetic body, wherein the recording layerprocessing step is conducted with the environment surrounding theintermediate maintained in a state of vacuum.

[0018] (2) The method of producing a magnetic recording medium accordingto (1), wherein

[0019] said recording layer processing step, said non-magnetic bodyfilling step, and said protective layer formation step are conductedsequentially with an environment surrounding said intermediatemaintained in a state of vacuum.

[0020] (3) The method of producing a magnetic recording medium accordingto (1) or (2), wherein

[0021] a dry process cleaning step, which uses either one of a gas and aplasma for removing foreign matter from an environment surrounding saidpartitioned recording elements, is provided between said recording layerprocessing step and said non-magnetic body filling step.

[0022] (4) The method of producing a magnetic recording medium accordingto any one of (1) through (3), wherein

[0023] a smoothing step for smoothing a surface of said partitionedrecording elements and said non-magnetic body is provided between saidnon-magnetic body filling step and said protective layer formation step.

[0024] (5) The method of producing a magnetic recording medium accordingto (4), wherein

[0025] said smoothing step is a dry plasma step which allows ions tocollide with a surface of said partitioned recording elements and saidnon-magnetic body at an incidence angle that is restricted to a valuewithin either one of a range from −10 to 15° and a range from 60 to 90°.

[0026] (6) The method of producing a magnetic recording medium accordingto (5), wherein said dry plasma step uses ion beam etching.

[0027] (7) The method of producing a magnetic recording medium accordingto any one of (1) through (6), wherein

[0028] in said recording layer processing step, said continuousrecording layer is partitioned by reactive ion etching using carbonmonoxide gas containing an added nitrogen based compound as a reactivegas.

[0029] (8) The method of producing a magnetic recording medium accordingto any one of (1) through (7), wherein

[0030] in said non-magnetic body filling step, said non-magnetic body isused to fill said grooves between said partitioned recording elementsusing either one of plasma CVD with bias power to said intermediate andbias sputtering.

[0031] (9) The method of producing a magnetic recording medium accordingto (8), wherein

[0032] said non-magnetic body filling step uses a material comprisingany one selected from the group consisting of an oxide material, anitride material, and a non-magnetic amorphous material as saidnon-magnetic body.

[0033] (10) The method of producing a magnetic recording mediumaccording to (9), wherein

[0034] said non-magnetic body filling step uses silicon dioxide as saidnon-magnetic body.

[0035] (11) The method of producing a magnetic recording mediumaccording to any one of (8) through (10), wherein

[0036] a barrier film formation step, which uses either one of a plasmaCVD method and a sputtering method for forming a barrier film on saidpartitioned recording elements, is provided between said recording layerprocessing step and said non-magnetic body filling step.

[0037] (12) The method of producing a magnetic recording mediumaccording to (11), wherein

[0038] said barrier film formation step forms a barrier film ofdiamond-like carbon.

[0039] (13) A production apparatus for a magnetic recording mediumcomprising:

[0040] recording layer processing device, which by forming a pluralityof grooves, with a minute spacing therebetween in a planar direction, inan intermediate from a production process for a magnetic recordingmedium produced by forming a continuous recording layer on top of asubstrate surface, partitions said continuous recording layer into aplurality of partitioned recording elements; and

[0041] vacuum retention device, which houses said recording layerprocessing device, and maintains an environment surrounding saidintermediate in a state of vacuum.

[0042] (14) The production apparatus for a magnetic recording mediumaccording to (13), wherein

[0043] non-magnetic body filling device for filling said grooves,between said partitioned recording elements with a non-magnetic body,and protective layer formation device for forming a protective layerthat protects said partitioned recording elements and said non-magneticbody are provided inside said vacuum retention device.

[0044] (15) The production apparatus for a magnetic recording mediumaccording to (13) or (14), wherein

[0045] dry process cleaning device for removing foreign matter from anenvironment surrounding said partitioned recording elements using eitherone of a gas and a plasma is provided inside said vacuum retentiondevice.

[0046] (16) The production apparatus for a magnetic recording mediumaccording to any one of (13) through (15), wherein

[0047] barrier film formation device for forming a barrier film on saidpartitioned recording elements using either one of a plasma CVD methodand a sputtering method is provided inside said vacuum retention device.

[0048] (17) The production apparatus for a magnetic recording mediumaccording to any one of (13) through (16), wherein

[0049] smoothing device for smoothing a surface of said partitionedrecording elements and said non-magnetic body is provided inside saidvacuum retention device.

[0050] In this specification, the term “barrier film” is used todescribe a thin film that separates the partitioned recording elementsfrom the non-magnetic body.

[0051] Furthermore, the term “diamond-like carbon” (hereafterabbreviated as DLC) is used to describe a material with an amorphousstructure containing carbon as the primary component, with a Vickershardness within a range from 200 to 8000 kgf/mm².

BRIEF DESCRIPTION OF THE DRAWINGS

[0052]FIG. 1 is a block diagram showing a schematic illustration of thestructure of a production apparatus for a magnetic recording mediumaccording to an embodiment of the present invention;

[0053]FIG. 2 is a side sectional view showing a schematic illustrationof the structure of an intermediate of a magnetic recording medium priorto processing with the same production apparatus;

[0054]FIG. 3 is a side sectional view showing a schematic illustrationof the structure of a magnetic recording medium following processingwith the same production apparatus;

[0055]FIG. 4 is a flowchart showing the steps for producing a magneticrecording medium with the same production apparatus;

[0056]FIG. 5 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following the transfer of apartition pattern into the third mask layer;

[0057]FIG. 6 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following the removal of thosesections of the third mask layer at the bottom surfaces of the concavesections;

[0058]FIG. 7 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following the removal of thosesections of the second mask layer at the bottom surfaces of the concavesections;

[0059]FIG. 8 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following the removal of thosesections of the first mask layer at the bottom surfaces of the concavesections;

[0060]FIG. 9 is a side sectional view showing a schematic illustrationof the shape of the above intermediate with the partitioned recordingelements formed;

[0061]FIG. 10 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following the removal of thosesections of the first mask layer remaining on the upper surface of thepartitioned recording elements;

[0062]FIG. 11 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following filling of the spacesbetween the partitioned recording elements with a non-magnetic body;

[0063]FIG. 12 is a side sectional view showing a schematic illustrationof the shape of the above intermediate following smoothing of thesurfaces of the partitioned recording elements and the non-magneticbody;

[0064]FIG. 13 is a photograph from an atomic force microscope showing anenlargement of the surface of the partitioned recording elements and thenon-magnetic body of a magnetic recording disk from an example of thepresent invention;

[0065]FIG. 14 is a photograph from an optical microscope showing anenlargement of the surface of the magnetic recording disk from the sameexample; and

[0066]FIG. 15 is a photograph from an optical microscope showing anenlargement of the surface of a magnetic recording disk from acomparative example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0067] As follows is a detailed description of embodiments of thepresent invention, with reference to the drawings.

[0068]FIG. 1 is a block diagram showing a schematic illustration of thestructure of a production apparatus for a magnetic recording mediumaccording to an embodiment of the present invention.

[0069] First, in order to facilitate a better understanding of thestructure of the production apparatus for magnetic recording media, asimple description is given of the structures of the magnetic recordingmedium intermediate and the magnetic recording medium itself.

[0070] As shown in FIG. 2, the magnetic recording medium intermediate 10comprises a glass substrate 12 with a backing layer 14, a soft magneticlayer 16, an orientation layer 18, a continuous recording layer 20, afirst mask-layer 22, a second mask layer 24, and a third mask layer 26formed sequentially thereon.

[0071] The material of the backing layer 14 is either Cr (chromium) or aCr alloy, the material of the soft magnetic layer 16 is an Fe (iron)alloy or a Co (cobalt) alloy, the material of the orientation layer 18is CoO, MgO or NiO or the like, and the material of the continuousrecording layer 20 is a Co (cobalt) alloy. Furthermore, the materials ofeach of the mask layers are TiN (titanium nitride) for the first masklayer 22, Ni (nickel) for the second mask layer 24, and a negativeresist (NEB22A, manufactured by Sumitomo Chemical Co., Ltd.) for thethird mask layer 26.

[0072] As shown in FIG. 3, the magnetic recording medium 30 is aperpendicular recording, discrete type recording disk, wherein thecontinuous recording layer 20 is partitioned into a plurality ofpartitioned recording elements 31 by minute spacings formed along theradial direction of the tracks, a non-magnetic body 32 fills the grooves33 between the partitioned recording elements 31, and a protective-layer34 and a lubricating layer 36 are formed sequentially on top of thepartitioned recording elements 31 and the non-magnetic body 32. Abarrier film 38 is formed between the partitioned recording elements 31and the non-magnetic body 32.

[0073] The material of the non-magnetic body 32 is SiO₂ (silicondioxide), the material for both the protective layer 34 and the barrierfilm 38 is the hard carbon film known as DLC described above, and thematerial of the lubricating layer 36 is PFPE (perfluoropolyether).

[0074] Returning to FIG. 1, the magnetic recording medium productionapparatus 40 comprises recording layer processing device 42 for formingthe partitioned recording elements 31 by forming the grooves 33 in theintermediate 10, dry process cleaning device 44 for removing foreignmatter from the environment surrounding the partitioned recordingelements 31, barrier film formation device 46 for forming the barrierfilm 38 on the partitioned recording elements 31, non-magnetic bodyfilling device 48 for filling the grooves 33 between the partitionedrecording elements 31 with the non-magnetic body 32, smoothing device 50for smoothing the surface of the partitioned recording elements 31 andthe non-magnetic body 32, protective layer formation device 52 forforming the protective layer 34 on the partitioned recording elements 31and the non-magnetic body 32, and vacuum retention device 56 whichhouses the recording layer processing device 42, the dry processcleaning device 44, the barrier film formation device 46, thenon-magnetic body filling device 48, the smoothing device 50, and theprotective layer formation device 52, and maintains the environmentsurrounding the intermediate 10 in a state of vacuum.

[0075] In addition, the production apparatus 40 also comprises transferdevice 58 for transferring a partition pattern onto the third mask layer26 of the magnetic recording medium intermediate 10, and lubricatinglayer formation device 54 for forming the lubricating layer 36 on top ofthe protective layer 34. The transfer device 58 and the lubricatinglayer formation device 54 are positioned outside the vacuum retentiondevice 56.

[0076] The recording layer processing device 42 comprises a plasmaprocessing device 60 for processing the third mask layer 26 with aplasma utilizing oxygen, ozone or a mixed gas thereof, an ion beametching device 62 for processing the second mask layer 24 with ion beametching utilizing Ar (argon) gas, a first reactive ion etching device 64for processing the first mask layer 22 with reactive ion etchingutilizing either CF₄ (tetrafluoromethane) gas or SF₆ (sulfurhexafluoride) gas, a second reactive ion etching device 66 forprocessing the continuous recording layer 20 with reactive ion etchingutilizing CO (carbon monoxide) gas containing added NH₃ (ammonia) gas,and a third reactive ion etching device 67 for removing those sectionsof the first mask layer 22 remaining on the surface of the partitionedrecording elements 31 with reactive ion etching utilizing either CF₄ gasor SF₆ gas.

[0077] The dry process cleaning device 44 is a dry process cleaningdevice that utilizes a plasma.

[0078] The barrier film formation device 46 is a CVD (Chemical VaporDeposition) device for forming the DLC barrier film 38 using CVD.

[0079] The non-magnetic body filling device 48 is a bias sputteringdevice for forming a film of the SiO₂ non-magnetic body 32 on top of thepartitioned recording elements 31 using bias sputtering.

[0080] The smoothing device 50 is an ion beam etching device forsmoothing the medium surface using ion beam etching with Ar gas.

[0081] The protective layer formation device 52 is a CVD device forforming the protective layer 34 of DLC using CVD.

[0082] The lubricating layer formation device 54 is an applicationdevice for applying a lubricating layer 36 of PFPE using dipping.

[0083] The vacuum retention device 56 comprises a vacuum chamber 68, anda vacuum pump 70 that interconnects with the vacuum chamber 68.

[0084] The transfer device 58 is a press device that utilizes anano-imprint method to press and transfer a pattern (not shown in thedrawings) prepared using lithography onto the third mask layer 26.

[0085] Next is a description of the actions of the magnetic recordingmedium production apparatus 40.

[0086]FIG. 4 is a flowchart showing the flow of processing for themagnetic recording medium production apparatus 40.

[0087] First, a magnetic recording medium intermediate 10 is prepared.The intermediate 10 is formed by using sputtering to form sequentially,on top of a glass substrate 12, a backing layer 14 with a thickness of300 to 2000 Å, a soft magnetic layer 16 with a thickness of 500 to 3000Å, an orientation layer 18 with a thickness of 30 to 300 Å, a continuousrecording layer 20 with a thickness of 100 to 300 Å, a first mask layer22 with a thickness of 100 to 500 Å, and a second mask layer 24 with athickness of 100 to 300 Å, and then using either spin coating or dippingto form a third mask layer 26 with a thickness of 300 to 3000 Å.

[0088] The transfer device 58 then uses a nano-imprint method totransfer the type of concave sections shown in FIG. 5, which correspondwith the partition pattern for the partitioned recording elements 31,into the third mask layer 26 of the intermediate 10.

[0089] At this point the intermediate 10 is transported into the vacuumchamber 68, and the plasma processing device 60 is used to process thethird mask layer 26 until those sections of the third mask layer 26 atthe bottom surfaces of the concave sections have been removed, as shownin FIG. 6. Those areas of the third mask layer 26 outside the concavesections are also partially removed, but the level difference betweenthese other areas and the bottom surfaces of the concave sections isretained.

[0090] Next, the ion beam etching device 62 is used to remove thosesections of the second mask layer 24 at the bottom surfaces of theconcave sections, as shown in FIG. 7. During this process a smallquantity of the first mask layer 22 is also removed. Furthermore, alarge proportion of those areas of the third mask layer 26 outside theconcave sections is also removed, although a small quantity stillremains.

[0091] Subsequently, the first reactive ion etching device 64 is used toremove those sections of the first mask layer 22 at the bottom surfacesof the concave sections, as shown in FIG. 8. At this time, the remainingquantity of those areas of the third mask layer 26 outside the concavesections is completely removed. Furthermore, a large proportion of thoseareas of the second mask layer 24 outside the concave sections is alsoremoved, although a small quantity still remains.

[0092] Next, the second reactive ion etching device 66 is used to removethose sections of the continuous recording layer 20 at the bottomsurfaces of the concave sections, thus partitioning the continuousrecording layer 20 into a plurality of partitioned recording elements 31with grooves 33 formed between the partitioned recording elements 31, asshown in FIG. 9 (S1).

[0093] During this process a small quantity of the orientation layer 18is also removed. Furthermore, the remaining quantity of those areas ofthe second mask layer 24 outside the concave sections is completelyremoved, and a large proportion of those areas of the first mask layer22 outside the concave sections is also removed, although a smallquantity still remains on the upper surface of the partitioned recordingelements 31.

[0094] This residual first mask layer 22 is completely removed with thethird reactive ion etching device 67, as shown in FIG. 10.

[0095] At this point, the dry process cleaning device 44 is used toremove foreign matter from the surface of the partitioned recordingelements 31 (S2).

[0096] Subsequently, as shown in FIG. 11, a CVD device is used to form abarrier film 38 of DLC, with a thickness of 10 to 200 Å, on top of thepartitioned recording elements 31 (S3), and the non-magnetic bodyfilling device 48 is then used to fill the grooves 33 between thepartitioned recording elements 31 with a non-magnetic body 32, using abias sputtering method (S4). The non-magnetic body 32 is formed so as tocompletely cover the-barrier film 38. Because the partitioned recordingelements 31 are covered and protected by the barrier film 38, theyundergo no deterioration during the bias sputtering of the non-magneticbody 32.

[0097] Next, the smoothing device 50 is used to remove a portion of thenon-magnetic body 32 by ion beam etching, until the upper surfaces ofthe partitioned recording elements 31 are exposed, as shown in FIG. 12,thereby smoothing the surface of the partitioned recording elements 31and the non-magnetic body 32 (S5). During this process, in order toensure high precision smoothing, the incidence angle of the Ar ions ispreferably set within a range from −10 to 15° relative to the surface.However if the surface of the partitioned recording elements 31 and thenon-magnetic body 32 has been produced with a good level of smoothnessduring the non-magnetic body filling step, then the incidence angle ofthe Ar ions may be set within a range from 60 to 90°. This type ofincreased incidence angle increases the processing speed, and enables animprovement in productivity. The barrier film 38 on the upper surface ofthe partitioned recording elements 31 may be either completely removed,or a portion may be left intact, although the non-magnetic body 32 abovethe partitioned recording elements 31 is completely removed.

[0098] The protective layer formation device 52 then uses a CVD methodto form a protective layer 34 of DLC, with a thickness of 10 to 50 Å, onthe upper surface of the partitioned recording elements 31 and thenon-magnetic body 32 (S6), and the structure is then transported out ofthe vacuum chamber 68.

[0099] Subsequently, the lubricating layer formation device 54 is usedto apply a lubricating layer 36 of PFPE, with a thickness of 10 to 20 Å,to the top of the protective layer 34, using a dipping method. Thiscompletes the formation of the magnetic recording medium 30 shown inFIG. 3.

[0100] Because the formation and processing of the partitioned recordingelements 31 is conducted with the environment surrounding theintermediate 10 in a state of vacuum, deterioration of the partitionedrecording elements 31 through oxidation or corrosion can be preventedduring processing.

[0101] In addition, the intermediate 10 is transported into the vacuumchamber 68 with the continuous recording layer 20 covered by the variousmask layers, and once inside the vacuum chamber 68 the partitionedrecording elements 31 are formed, filling of the non-magnetic body 32 isperformed, and the protective layer 34 is formed on top of thepartitioned recording elements 31 and the non-magnetic body 32 beforethe magnetic recording medium 30 is transported out of the vacuumchamber 68, and consequently the partitioned recording elements 31 (andthe continuous recording layer 20) are isolated from atmospheric oxygenand the like at all times, meaning deterioration of the partitionedrecording elements 31 can be even more reliably prevented.

[0102] Furthermore, because each of the steps utilizes a dry process,problems that arise when wet processes are used, such as deteriorationof the partitioned recording elements 31 caused by the process liquids,or contamination of the surface of the partitioned recording elements 31caused by foreign matter within the process liquids or cleaning liquids,can be avoided.

[0103] In other words, the magnetic recording medium productionapparatus 40 displays superior reliability, and is able to reliablyprevent deterioration during formation of the partitioned recordingelements 31.

[0104] Furthermore, because each of the steps utilizes a dry process,transportation of the work in progress is easier than processes whichcombine wet and dry processes, meaning the magnetic recording mediumproduction apparatus 40 displays good levels of production efficiency.

[0105] In the present embodiment, the steps from the etching of thethird mask layer 26 through to the formation of the protective layer 34are all performed inside the vacuum chamber 68, but the presentinvention is not restricted to this arrangement, and provided thepartitioned recording elements 31 and the continuous recording layer 20are isolated from the atmosphere to prevent deterioration of thepartitioned recording elements 31, the steps for processing each of themasks, prior to the processing of the continuous recording layer 20, mayalso be performed outside of the vacuum chamber 68. However, duringprocessing of the first mask layer 22, sections of the continuousrecording layer 20 are exposed (see FIG. 9), and consequently theprocessing of the first mask layer 22 is preferably conducted inside thevacuum chamber 68.

[0106] Furthermore, in the present embodiment three mask layers ofdifferent materials are formed on the continuous recording layer 20, anda four-stage dry etching process is then used to form the grooves 33 inthe intermediate 10 and partition the continuous recording layer 20, butthere are no particular restrictions on the type of dry etching used,the materials used for the mask layers, the number of mask layers, orthe thickness of the mask layers, provided the continuous recordinglayer 20 is able to be partitioned with a high level of precision.

[0107] Furthermore, in the present embodiment a dry process cleaningoperation using a plasma is used for removing foreign matter from thesurface of the partitioned recording elements 31, but the presentinvention is not restricted to this method, and the foreign matter onthe surface of the partitioned recording elements 31 could also beremoved by a dry process cleaning operation-using a gas.

[0108] In addition, in the present embodiment the non-magnetic bodyfilling device 48 uses a bias sputtering method, but the presentinvention is not restricted to this method, and the filling of thenon-magnetic body could also be performed using a plasma CVD method withbias power to said magnetic recording medium intermediate 10.

[0109] Furthermore, in the present embodiment the magnetic recordingmedium 30 is a perpendicular recording, discrete type magnetic disk inwhich the partitioned recording elements 31 are arranged with minutespacings in the track radial direction positioned therebetween, but thepresent invention is not restricted to this case, and can of course alsobe applied to the production of magnetic disks in which the partitionedrecording elements are arranged with minute spacings in the trackcircumferential direction (the sector direction) positionedtherebetween, magnetic disks in which the partitioned recording elementsare arranged with minute spacings in both the track radial direction andthe track circumferential direction positioned therebetween, andmagnetic disks in which the partitioned recording elements form ahelical shape. Furthermore, the present invention can also be applied tothe production of magneto-optical disks such as MO disks, and othernon-disk type discrete type magnetic recording media such as magnetictapes and the like.

[0110] Furthermore, in the present ecbidiment the magnetic recordingmedium production apparatus 40 is equipped with a separate processingdevice for each of the steps, but the present invention is notrestricted to such a configuration, and a plurality of steps could alsobe conducted with a single device. For example, the step for processingthe first mask layer 22, and the step for removing the residual firstmask layer 22 from the surface of the partitioned recording elements 31could be conducted using the same reactive ion etching device, usingeither CF₄ or SF₆ as the reactive gas. In addition, the step forprocessing the second mask layer 24, and the step for smoothing thepartitioned recording elements 31.and the non-magnetic body 32 could beconducted using the same Ar gas ion beam etching device. Theserationalizations enable reductions in both the size and the cost of theproduction apparatus.

EXAMPLE

[0111] Using the embodiment described above, the processing devicesprovided inside the vacuum chamber were used to prepare a magneticrecording disk with the continuous recording layer and the partitionedrecording elements isolated from the atmosphere. FIG. 13 is a photographfrom an atomic force microscope showing an enlargement of the surface ofthe partitioned recording elements and the non-magnetic layer followingsmoothing by ion beam etching. Measurement of the surface roughness ofthe partitioned recording elements and the non-magnetic layer revealed amaximum level difference of 2.88 nm, and a center line average roughnessRa of 0.723 nm. These results confirm that in this example, the surfaceof the partitioned recording elements and the non-magnetic layer havebeen satisfactorily smoothed, without the use of a wet process such asCMP. Furthermore, when a surface defect inspection device was used toinspect the surface of the medium for foreign matter, two pieces offoreign matter of size 0.3 to 0.5 μm were identified. No foreign matterlarger than 1.0 μm, nor any foreign matter of size 0.5 to 1.0 μm wasfound. In addition, the surface of the magnetic recording disk wasobserved through an optical microscope, both immediately followingproduction, and then again after standing for approximately 48 hours ina high temperature, high humidity environment (temperature: 80° C.,humidity: 80%), and on both occasions no corrosion of the partitionedrecording elements was visible. FIG. 14 is a photograph from the opticalmicroscope showing an enlargement of the surface of the magneticrecording disk of the example after standing for approximately 48 hoursin the high temperature, high humidity environment.

Comparative Example

[0112] A magnetic recording disk was prepared in a similar manner to theexample above, but with the exception that the processing devices werenot housed inside a vacuum chamber, so that the continuous recordinglayer and the partitioned recording elements were permitted to come incontact with the atmosphere. When a surface defect inspection device wasused to inspect the surface of the partitioned recording elements andthe non-magnetic body for foreign matter, a total of 193 pieces offoreign matter, including 28 pieces of size 0.3 to 0.5 μm, 38 pieces ofsize 0.5 to 1.0 μm, and 127 pieces larger than 1.0 μm were identified.Furthermore, when the surface of the magnetic recording disk wasobserved through an optical microscope, both immediately followingproduction, and then again after standing for approximately 48 hours ina high temperature, high humidity environment, although no corrosion ofthe partitioned recording elements was evident initially, after standingfor 48 hours following production, a plurality of black spots wereobserved, indicating corrosion of the partitioned recording elements.FIG. 15 is a photograph from the optical microscope showing anenlargement of the surface of the magnetic recording disk of thecomparative example after standing for approximately 48 hours in thehigh temperature, high humidity environment.

[0113] In other words, corrosion of the partitioned recording elementswas prevented in the example, and the incorporation of foreign matterwas also-markedly reduced when compared with the comparative example.

[0114] As described above, the present invention enables the efficientproduction of a discrete type magnetic recording medium with reliableprevention of any deterioration of the partitioned recording elements.

What is claimed is:
 1. A method of producing a magnetic recording mediumcomprising: a recording layer processing step, which by forming aplurality of grooves, with a minute spacing therebetween in a planardirection, in an intermediate from a production process for a magneticrecording medium produced by forming a continuous recording layer on topof a substrate surface, partitions said continuous recording layer intoa plurality of partitioned recording elements; a non-magnetic bodyfilling step for filling said grooves between said partitioned recordingelements with a non-magnetic body; and a protective layer formation stepfor forming a protective layer that protects said partitioned recordingelements and said non-magnetic body, wherein said recording layerprocessing step is conducted with an environment surrounding saidintermediate maintained in a state of vacuum.
 2. The method of producinga magnetic recording medium according to claim 1, wherein said recordinglayer processing step, said non-magnetic body filling step, and saidprotective layer formation step are conducted sequentially with anenvironment surrounding said intermediate maintained in a state ofvacuum.
 3. The method of producing a magnetic recording medium accordingto claim 1, wherein a dry process cleaning step, which uses either oneof a gas and a plasma for removing foreign matter from an environmentsurrounding said partitioned recording elements, is provided betweensaid recording layer processing step and said non-magnetic body fillingstep.
 4. The method of producing a magnetic recording medium accordingto claim 1, wherein a smoothing step for smoothing a surface of saidpartitioned recording elements and said non-magnetic body is providedbetween said non-magnetic body filling step and said protective layerformation step.
 5. The method of producing a magnetic recording mediumaccording to claim 4, wherein said smoothing step is a dry plasma stepwhich allows ions to collide with a surface of said partitionedrecording elements and said non-magnetic body at an incidence angle thatis restricted to a value within either one of a range from −10 to 15°and a range from 60 to 90°.
 6. The method of producing a magneticrecording medium according to claim 5, wherein said dry plasma step usesion beam etching.
 7. The method of producing a magnetic recording mediumaccording to claim 1, wherein in said recording layer processing step,said continuous recording layer is partitioned by reactive ion etchingusing carbon monoxide gas containing an added nitrogen based compound asa reactive gas.
 8. The method of producing a magnetic recording mediumaccording to claim 1, wherein in said non-magnetic body filling step,said non-magnetic body is used to fill said grooves between saidpartitioned recording elements using either one of plasma CVD with biaspower to said intermediate and bias sputtering.
 9. The method ofproducing a magnetic recording medium according to claim 8, wherein saidnon-magnetic body filling step uses a material comprising any oneselected from the group consisting of an oxide material, a nitridematerial, and a non-magnetic amorphous material as said non-magneticbody.
 10. The method of producing a magnetic recording medium accordingto claim 9, wherein said non-magnetic body filling step uses silicondioxide as said non-magnetic body.
 11. The method of producing amagnetic recording medium according to claim 8, wherein a barrier filmformation step, which uses either one of a plasma CVD method and asputtering method for forming a barrier film on said partitionedrecording elements, is provided between said recording layer processingstep and said non-magnetic body filling step.
 12. The method ofproducing a magnetic recording medium according to claim 11, whereinsaid barrier film formation step forms a barrier film of diamond-likecarbon.
 13. A production apparatus for a magnetic recording mediumcomprising: recording layer processing device, which by forming aplurality of grooves, with a minute spacing therebetween in a planardirection, in an intermediate from a production process for a magneticrecording medium produced by forming a continuous recording layer on topof a substrate surface, partitions said continuous recording layer intoa plurality of partitioned recording elements; and vacuum retentiondevice, which houses said recording layer processing device, andmaintains an environment surrounding said intermediate in a state ofvacuum.
 14. The production apparatus for a magnetic recording mediumaccording to claim 13, wherein non-magnetic body filling device forfilling said grooves between said partitioned recording elements with anon-magnetic body, and protective layer formation device for forming aprotective layer that protects said partitioned recording elements andsaid non-magnetic body are provided inside said vacuum retention device.15. The production apparatus for a magnetic recording medium accordingto claim 13, wherein dry process cleaning device for removing foreignmatter from an environment surrounding said partitioned recordingelements using either one of a gas and a plasma is provided inside saidvacuum retention device.
 16. The production apparatus for a magneticrecording medium according to claim 13, wherein barrier film formationdevice for forming a barrier film on said partitioned recording elementsusing either one of a plasma CVD method and a sputtering method isprovided inside said vacuum retention device.
 17. The productionapparatus for a magnetic recording medium according to claim 13, whereinsmoothing device for smoothing a surface of said partitioned recordingelements and said non-magnetic body is provided inside said vacuumretention device.